The GSTP1 A1578G polymorphism and the risk of childhood acute lymphoblastic leukemia: results from an updated meta-analysis.

Studies investigating the association between the glutathione S-transferase P1 (GSTP1) A1578G polymorphism and the risk of childhood acute lymphoblastic leukemia (ALL) report conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline, Embase, China National Knowledge Infrastructure, and Wangfang databases for studies of the polymorphism and ALL. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for the GSTP1 polymorphism and childhood ALL were calculated in a fixed-effect model. Pooled ORs were calculated for a co-dominant model (GG vs AA, AG vs AA), a dominant model (GG + AG vs AA), and a recessive model (GG vs AA + AG). Analyses were also performed in subgroups stratified by race, study design, genotyping methods, and study sample size. This meta-analysis included 8 case-control studies with 1384 childhood ALL cases and 1755 controls. Overall, the variant genotypes (GG and AG) of A1578G were not associated with childhood ALL risk, when compared with the wild-type homozygote AA genotype (GG vs AA, OR = 1.09, 95%CI = 0.84-1.43; AG vs AA, OR = 1.05, 95%CI = 0.91-1.23). Similarly, no associations were found in the dominant and recessive models (dominant model, OR = 1.06, 95%CI = 0.92-1.23; recessive model, OR = 1.09, 95%CI = 0.84-1.43). Stratified analyses did not detect significant association in any subgroup. No heterogeneity or publication bias was observed in the present study. This updated meta-analysis indicates that the GSTP1 A1578G polymorphism is not associated with the risk of childhood ALL. In the future, additional studies in Asian and African-American patients should be performed to re-evaluate the association in these populations.